Eccentric throttle pulleys... anyone running one on a 7M TB?

[CRE]

So I've been thinking I'd really like to get an eccentric throttle cable pulley for my TB. I don't know if anyone makes one already or if I'd have to get one fabbed. My low throttle angle responsiveness is just too sensitive for my tastes.

So, the questions that remain are:

Does anyone know of a compatible one or one that could easily be modded to fit OR have any suggestions on where I could get one designed and built?

Are there any potential issues (other than making sure the cable doesn't hop off)? I can't think of any.

 

[adampecush]

what kind of throttlebody do you have?

I made an eccentric TB for my q45 TB. It improved my situation significantly.

http://www.supramania.com/forums/showthread.php?t=102862&highlight=eccentric&page=3

I'm looking into having a small batch of these built, but I need at least 10 people to make it cost effective. So far, only around 5 have shown interest.

 

[supra90turbo]

What would the cost be? As this is part of my future plans, I may be in for one.

 

[adampecush]

can't give anything concrete yet, but I'd imagine 80-100 CAD each (unfinished) I'd imagine anodizing would add ~20 bucks to that price. Keep in mind that these are rough estimates.

 

[gofastgeorge]

I made mine from welding one up, with the center of the pulley part offset from the center from the throttle shaft.
It isn't a true ecentric, but it works OK.
Took a lot of diken around to finally get the action I wanted.

I am waiting for adampecush's billet one (or 2!)
They are available in Japan, but cost a lot.

By the way, I'd like mine non-anodized (hint, hint):naughty:

 

[CRE]

I'm running the stock GE TB. Adam, what are the dimensions of that pulley?

 

[GrimJack]

I'd probably be in for one of those if I can make it connect to my generic TB... Hell, at that cost, I'll buy one even if it won't fit. I'll use it for a paperweight otherwise.

 

[adampecush]

I'm running the stock GE TB. Adam, what are the dimensions of that pulley?

the "pull" radius is 28.5 mm (to maintain the pull distance of the stock pedal).
Centre "bore" is offset -8.7 mm in the y-direction and -6.4 mm in the x-direction.

 

[CRE]

I was doing some work on my car today and was reminded of what a majestic mess the stock throttle body pulley and linkage system is.... :thumbsdow I'm going to have to do a decent amount of work to get what I'm looking for out of the stock TB... I wonder if just movint the pivot on one of the pulleys would do the trick? :icon_conf

I need to do something though, my low throttle angle drivability just sucks... WAY too touchy. I've been trying for years to find an adjustment which would smooth it out, but no luck.

 

[IJ.]

MoTeC DBW FTW
(can be as eccentric as you chose)

 

[CRE]

MoTeC DBW FTW
(can be as eccentric as you chose)

Yup, I'm thinking of either trying to modify the spare TB I have or looking for a generic TB to use... then perhaps shorten the cable and have it pull from the driver's side of the bay, pulling from the bottom of the TB as opposed to the top as is the case with the stock setup... Like I said though. It's going to take some work. I'm just not sure if I can get it to work with a direct cable or if I'll have to use a second pulley.

 

[IJ.]

I've ran my car with the throttle set up 1:1 and it's almost undriveable, very fussy and jerky, I run it 0>50 @ half so 10% at the pedal = 5% at the TB then linear from 50%>100%.

Make it all behave so much nicer in day to day traffic.

 

[CRE]

Hmm, I wonder what the ratio of the stock N/A TB is... whatever it is it's not working for me.

 

[adampecush]

I've ran my car with the throttle set up 1:1 and it's almost undriveable, very fussy and jerky, I run it 0>50 @ half so 10% at the pedal = 5% at the TB then linear from 50%>100%.

Make it all behave so much nicer in day to day traffic.

Its true, 1:1 is unbearable. A grabby clutch makes things much worse.

 

[adampecush]

I was doing some work on my car today and was reminded of what a majestic mess the stock throttle body pulley and linkage system is.... :thumbsdow I'm going to have to do a decent amount of work to get what I'm looking for out of the stock TB... I wonder if just movint the pivot on one of the pulleys would do the trick? :icon_conf

I need to do something though, my low throttle angle drivability just sucks... WAY too touchy. I've been trying for years to find an adjustment which would smooth it out, but no luck.

There must be something wrong with your setup if you still have the stock TB. I never had any driveability issues with the stock setup since it is effectively an eccentric system. (that, and the tb is relatively small). My issues arose when using a Q45 TB (linkage removed for hood clearance) with a direct pull pulley.

Have you verified the full-range operation of your TPS? You shouldn't have issues with the stock set-up.

 

[IJ.]

Its true, 1:1 is unbearable. A grabby clutch makes things much worse.

OS Giken Twin with Solid unsprung Ceramic discs and double diaphram

 

[CRE]

Yeah, I've checked, no flat spots, IDL switch is properly set, proper slack in the cable, no wobble at any of the pulley pivots... I suspect it may be due to the replacement of the VAF with something that's actually capable of seeing and reporting those small and fast changes that you see at low throttle angles; I don't know though. AJ's 88 has the same issue with his built N/A.

I checked everything again today: the TPS and all the throttle components (linkages, pulleys ant the roller that's on the pulley which actually pulls the main pulley... all fine, no worn in grooves, no excess tension or binding.

Looking that the TB, if it is eccentric then the curve seems pretty shallow... I didn't take measurements though.